JPS5984978A - Liquefaction of coal - Google Patents

Abstract

PURPOSE:To obtain a liquefied product having high light oil content in high efficiency with reduced consumption of hydrogen, by extracting a specific liquefied coal oil obtained by the second-stage of coal liquefaction process as a hydrogen-donative solvent, treating the coal, and converting to asphaltene. CONSTITUTION:Coal is converted to a slurry composed mainly of asphaltene in the presence of a hydrogen-donative solvent, and the slurry is hydrogenated in the presence of a catalyst containing Ni-Co and/or Co-Mo metal sulfide. In the above second-stage coal liquefaction, the hydrogenated coal oil having a boiling point of >=200 deg.C and containing >=5wt% of a fraction having a boiling point of >=450 deg.C is separated as the hydrogen-donative solvent from the liquefied coal oil obtained by the second stage, and the coal is treated with the hydrogen- donative solvent at 200-320 deg.C for >=5min under a pressure higher than the vapor pressure of the liquefied coal oil at 320 deg.C. The obtained product is used for the conversion of the product composed of asphaltene to a slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coal liquefaction method capable of obtaining a coal liquefaction product.

Many methods are known in the art for converting coal to produce useful stone Ml+-like liquid products.

To liquefy coal, there are two methods: carbonization liquefaction method in which coal is heated to high humidity and the pyrolysis distillate is extracted once, solvent extraction liquefaction method in which coal is extracted with a solvent, hydrogen transfer or hydrogen donating solvent. The solvent decomposition and liquefaction method involves simultaneously extracting and hydrogenating coal, the extraction hydrogenation and liquefaction method involves solvent extraction under the supply of high-pressure hydrogen gas (molecular hydrogen), and the method using a catalyst under the supply of high-pressure hydrogen gas. There are direct hydrogenation and liquefaction methods in which coal is hydrocracked.0 If each of the above-mentioned liquefaction methods is viewed as a single one-stage liquefaction method, the carbonization liquefaction method has a low yield of liquefied oil, and +1:,
The solvent extraction liquefaction method using benzene, toluene, xylene, carbolic acid, creosote oil, cresol, anthracene oil, etc., which is known from 1. there were. It has been known for a long time that hydrogenated aromatic compounds, such as tetralin, have the effect of donating hydrogen to and stabilizing the fragments that are generated when the cross-linked structure of coal molecules is thermally decomposed during the initial reaction of coal liquefaction. The solvent decomposition liquefaction method and extraction hydrogenation liquefaction method using solvents containing such substances are
Although it has the characteristic that a high yield of liquefied oil can be obtained in a relatively short time, it has the drawback that the obtained liquefied oil generally has a high proportion of high molecular weight liquefied oil, and the progress of lightening is insufficient. or,
In the extraction hydrogenation liquefaction method, attempts have been made to make the liquefied oil lighter than the solvent decomposition liquefaction method through a relatively long treatment time, but this is due to the action of catalyst substances coexisting with the coal ash. This method relies heavily on the effects of hydrocracking, and is a passive method that is highly dependent on the type of hot coal. The direct hydrogenation and liquefaction method, which actively hydrocracks coal by adding a catalyst, can solve the disadvantages of the liquefaction method described above in terms of liquefaction yield and lightening of liquefied oil. However, the reaction conditions such as reaction humidity and reaction pressure are harsh;
Hydrogen consumption plays a large role in the economics of coal liquefaction.
It is well known that it has significant drawbacks compared to the two-book betting method.

In order to obtain liquefied oil with a high liquefaction rate and a lighter weight from coal, it is essential to use hydrogen in some kind of formula, and in the liquefaction method that uses hydrogen, this hydrogen consumption fi , Keeping the accent to a small level is a fundamental way to increase economic efficiency.

The main reaction of coal liquefaction is a sequential reaction that proceeds in the order of coal → Blair asphaltene (pyridine soluble, benzene insoluble) → asphaltene (benzene soluble, pentane insoluble) → oil, and the reaction rate decreases significantly as it progresses to the later stages. It is well known that this will happen. In order to ease the reaction conditions and reduce hydrogen consumption, there is a method to stop the primary liquefaction reaction of coal → asphaltene, which progresses rapidly by heating, and to suppress the production of gases such as methane. In order to effectively promote hydrogenolysis, it is desirable not to coexist with substances that can poison the catalyst.

From this point of view, the reaction is divided into the coal->asphaltene reaction, which has a fast reaction rate, and the asphaltene->MI+ reaction, which has a slow reaction rate, and removes the catalyst poisoning substance from the - entry compound and converts Co- into 4o and N1-. A two-stage liquefaction method has been proposed in which secondary liquefaction is promoted using a catalyst such as Mo/alumina.

As the primary liquefaction (first stage reaction step) of the two-stage liquefaction method, the solvent decomposition liquefaction method and the extraction hydrogenation liquefaction method described above are applied, and both use a hydrogen transfer or hydrogen donating solvent as the medium oil for the liquefaction reaction. Use. The extraction hydrogenation liquefaction method uses a relatively light medium oil mainly consisting of partially hydrogenated aromatic rings of two-ring aromatic hydrocarbons as a hydrogen-donating solvent, and involves a relatively long reaction time under high-pressure hydrogen gas supply. This is a method of carrying out the liquefaction reaction of coal → asphaltene over time, and in the solvent decomposition liquefaction method, preferably 5.
Mixing a hydrotreated fraction with a boiling point of 4,500 or higher with medium medium oil mainly consisting of partially hydrogenated aromatic rings of ~5fJA polycyclic aromatic hydrocarbons and their alkyl derivatives. This is a method in which the primary liquefaction reaction of coal to asphaltene is carried out under relatively conventional low pressure conditions without using hydrogen gas, and in a relatively short reaction time.

The primary liquefaction reaction of coal → asphaltene has a faster reaction rate than the secondary liquefaction reaction of asphaltene → oil. In both the solvent decomposition liquefaction method and the extraction hydrogenation liquefaction method described above, the reaction humidity is further increased. For example, a high-temperature, short-time reaction two-stage liquefaction method has been proposed in which the primary liquefaction reaction is carried out in a short time of 5 to 4 minutes.
) However, the first stage reaction of this method is
The ratio of pre-asphaltene to asphaltene in the liquefied product is high, and even though the liquefaction rate is satisfied, a liquefied product with a sufficient degree of lightening cannot be obtained, and the weight of the liquefied residue due to high molecular weight and high viscosity. There are major drawbacks such as separability and fractional decomposition of the second (dihydrogenolysis reaction).Furthermore, because the reaction is a high-temperature and short-time reaction, the degree of lightening of the obtained liquefied product is limited. There are disadvantages in that the relative loss of media oil and the amount of hydrogen consumption are high, and hydrogen consumption is not efficient.

In view of the above-mentioned circumstances, the present invention has conducted various studies on practical and economical technologies for a two-stage liquefaction method in which the first stage liquefaction reaction is a short-time contact reaction. I came to make the invention described below. That is, the present invention provides a new and improved liquefaction reaction method using a solvent decomposition liquefaction method, in which the total hydrogen consumption is small, and the degree of lightness of the liquefied product can be increased while the contact reaction continues for a short time. Therefore, a new and improved two-stage liquefaction method using this as the first-stage liquefaction reaction is provided.

That is, in the present invention, as a medium oil for the liquefaction reaction, coal obtained by hydrotreating pre-natural coal in the presence of a catalyst containing a metal sulfide of group (I) and/or group (I) of the periodic table of elements is used. The medium oil is divided into a light medium oil mainly composed of hydrides with a boiling point of 200 to 450°C and a heavy medium oil mainly composed of components with a boiling point of 4500 or higher, and the light medium oil is divided into In contrast, the mixture was adjusted so that the amount of heavy medium oil was 5 weight or more (hereinafter referred to as 1 for liquefied medium), and the liquefied medium oil was added to 1αr1 coal to give 200-520
After holding for 5 to 120 minutes under 7Ilii degree conditions, the liquefied product obtained by reaction treatment for 5 to 20 minutes at reaction humidity of 4 () 0 to 480°C, preferably L< is the main component. A certain asphaltene component is separated, a light medium oil is added, and hydrogenation is carried out at a reaction humidity of 280C to 480C in the presence of a catalyst containing a metal sulfide of Group I and/or Group VI of the Periodic Table of Elements. The main purpose of this method is to use 4i1 (quality coal liquefied oil) to perform chemical fractionation.The operation and effects of this method will be explained below.

In general, partially hydrogenated aromatic compounds such as tetralin are known as solvents that are effective for coal and effective for hydrogen transfer or hydrogen donation.

In addition to low-boiling substances such as tetralin, 5-5 ring polycyclic aromatic hydrocarbons and their derivatives, such as phenanthrene, anthracenefluoranthene, hylene, and chrysene, are present as hydrogen-donating substances in coal before it grows. There are hydrogen-donating substances with relatively high boiling points, such as cholanthrene, benzo(a)hylene, etc., and partially hydrogenated products of alkyl derivatives thereof. On the other hand, in the coal liquefaction reaction, the cross-linked structure in the coal molecules is thermally decomposed in the initial reaction to generate fragments, and the above-mentioned hydrogen-transferring or hydrogen-donating substances are involved in these thermally unstable fragments. It is said that pre-asphaltenes, asphaltenes, oil, and gas with lower molecular weight than stabilized coal are produced by supplying hydrogen. As a result of further study of this initial reaction process, the present inventors found that the main reaction of this initial reaction proceeds as a sequential reaction of coal → breasphaltene → asphaltene, and in particular, the reaction of preasphaltene → asphaltene requires sufficient hydrogen donation. It was confirmed that satisfactory progress could not be made unless a neutral solvent or excited hydrogen was present.

In other words, the reaction of coal → breasphaltene, which starts at an early stage due to the initial reaction, is stabilized by migrating hydrogen or by donating hydrogen, but the necessary amount of hydrogen is extremely small.
If it is a little, it is estimated to be 1i11?1. Furthermore, it has been experimentally shown that the coal→breasphaltene pole (in the initial reaction stage, if more hydrogen-donating solvent is present than the required amount, if the temperature conditions are satisfied, it is necessary for fragment stabilization). It has been confirmed that the donated hydrogen other than the hydrogen is released as molecular hydrogen.

In other words, as explained above, the main reaction of the first stage liquefaction reaction is the conversion of coal to asphaltene, and it is easy to see that the liquefaction reaction product is heavy, even though the conventional short-time contact reaction VC can be carried out. can be understood. Therefore, the present inventors have discovered that the first-stage liquefaction product can be made lighter by actually pre-treating the coal as a pre-stage of the first-stage liquefaction reaction. In general, it is known that when sub-bituminous coal and bituminous coal are mixed and heated with an aromatic compound that has been hydrogenated by 1ζ, such as tetralin, they swell. This reaction is considered to be a dissolution reaction of coal, and it has been observed that the viscosity of coal slurry increases as a physical phenomenon. Conventionally, this swelling phenomenon occurs within 9τ of heating the coal slurry, which may cause poor flow of the coal slurry in the heating tube due to the increase in viscosity of the coal slurry. : Consideration was given to preventing flow defects within the heating tube.

On the other hand, the present inventors focused on the fact that this coal swelling phenomenon is a dissolution reaction of coal in a solvent, and by completely performing this coal swelling phenomenon as a pre-stage of the coal liquefaction reaction, the coal liquefaction product can be produced. It has been found that the coal liquefaction product has a remarkable effect in lightening the coal, and further, by using the above-mentioned liquefaction medium oil as a solvent during pre-treatment of mixing coal and a solvent, it has been found that further lightening of the coal liquefaction product can be achieved.

Hereinafter, details of the present invention will be explained along with the drawings.

FIG. 1 is a diagram showing a flow of an embodiment of the method of the present invention.

In FIG. 1, raw coal 1 is mixed and adjusted as a slurry with liquefied medium oil 2 in a slurry adjustment tank 11f], and the coal slurry 5 is heated in a slurry heater 120.
The heated coal slurry is heated to 11'C at 00 to 520 degrees Celsius, and the slurry 1) is heated to 11'C in the treatment tank 150.
You will be left stunned for 120 minutes.

The operating pressure of the slurry pretreatment tank 150 is equal to or higher than the vapor pressure when the liquefied medium oil is heated at a temperature of 620°C,
The raw coal that is pretreated while maintaining the pressure for a moment swells in the liquefied medium oil 2, and its viscosity becomes several to several tens of times that of the coal slurry 5 supplied to the slurry heater 120, resulting in a short-time contact reaction. will be easily promoted. The pretreated coal slurry 5 is supplied to the coal liquefaction reactor 140,
A short time contact reaction is carried out as a first stage liquefaction reaction.

'The operating conditions of coal liquefaction and profit 140 are 400-480
℃ for 5 to 20 minutes, the output is 40% of the liquefied medium oil.
It is necessary that the vapor pressure is higher than that when maintained at a temperature of 0 to 480C, and in the coal liquefaction reactor 140, coal is converted into gas, produced oil, asqualtenes, and preasphaldenes. Among the liquefied products, gas-containing 4+
The light oil of the mature oil is separated, and the liquefied reaction product gas and light oil 7 are discharged to the outside of the process line. The liquefied oil slurry 6 is supplied to the solid-liquid separator 150.

The solid-liquid separator 150 is operated under moderate temperature and pressure, and discharges mainly unreacted coal and ash in the coal liquefaction product ffl + slurry as liquefaction residue 9 to the outside of the process system, and removes other coal liquefaction products. Oil, asphaltene and pre-asphaltene content 1d 14 Liquefied product oil with outside mold removed 8
is supplied to the hydrogenation reactor 160 as

In the hydrogenation reactor 16o, Ni-MQ system and C.

- In the presence of a catalyst containing a MO-based metal sulfide, 8 parts of liquefied oil and 1 part of hydrogen are reacted under appropriate reaction pressure, temperature, and time, and the liquefied oil is reacted with liquefaction reaction vc.
The reaction is processed to include a large amount of optimal partial hydrogenation. Among the reaction products of the reaction, the hydrogenation reaction product gas 12 is discharged to the outside and is supplied to the hydrogenation and liquefaction tank 111 distillation column +70 containing a large amount of hydrogenated product.

The distillation column 170 is rotated under moderate 77111 degrees I-E-force and operated to produce the liquefied medium oil 2 required for the liquefaction reaction. 2 bottles of liquefied medium oil, boiling point 200-4
It is a coal-based oil that is mainly composed of a 50° C. fraction before hydrogenation, and contains at least 5 or more fractions with a boiling point of 450° C. or higher. Naka, Ho, the relevant distillation column 17
From 0, heavy oil is transferred to the outside of the thread as product oil 15.
13 will be served.

The method of the present invention will be explained in detail below with specific examples.

Example 1: Liquefaction of Australian submerged coal was carried out under the conditions shown in Table 1VC, and the results obtained are shown graphically in Table 1 and Figures 2 to 4.

Figure 2 is a chart to clarify the effects of coal pretreatment. As is clear from the cause, Run Zui A, which did not pre-treat the coal, and Run NαI, J, which pre-treated the coal,
L, IJ coal conversion rate (+0O-TI (Fr%) ke II
′! However, compared to asphaltene/breasphaltene in coal liquefaction product oil, fltfJ of 1 to M with treatment is 4 to 5 times that of A without treatment, indicating that the lightening is very advanced. I understand. Figure 5 is a diagram of Liquids II (clarifying the effects of body oil properties).

As is clear from the origin, the boiling point of liquid medium oil is 200~4
As the 450°C fraction increases in the 50°C fraction, the coal conversion rate and asphaltene/pre-asphaltene ratio increase, and the tendency toward lighter weight increases, resulting in -10,000 liquid medium oil'l
It can be seen that when only the r, ~200C fraction is considered, the coal conversion rate and asphaltene/pre-asphaltene ratio are very low.

Furthermore, Figure 4 shows that when coal 0↑I treatment is feared (T1t+nm
This is a diagram to clarify the effects of the properties of the liquid medium oil (r, O, P, Q), and although the coal turnover rate is constant at Cg due to its origin, it is It can be seen that the ratio i becomes better by adding 5 wt% or more of the 450C'' fraction.
''- Even if distillation 50 lJt is mixed, coal conversion...β
There is no significant change in the degree of weight reduction, but 50wt
% or more, the viscosity of the solvent increases, making the operation impractical. Therefore, it is preferable that the upper limit of the mixing proportion of the 450C+ fraction is S U wtφ.

FIG. 5 is a chart for clarifying the relationship with liquefaction reaction time. As is clear from the cause, the liquefaction reaction time is 5~
15 minutes is I[・k;IN, even if it is shorter than this, Ji <
However, it can be seen that both the coal conversion rate and asphaldene/breasphaltene ratio decrease.

In addition, CO-MO and Ni-Mo, which are commercially available hydrogenation catalysts, were used as hydrogenation catalysts for liquid medium oil, but both the 7f conversion rate and the eave IjJj conversion rate showed a change in H.
-There was no (T(u, n to Nα, N screw light).

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the flow of one embodiment of the method of the present invention: IP example, and FIGS. 2 to 5 are charts showing the results obtained in the leprosy example of the present invention. Sub-agent 1) Meikoku agent Ryo Hagiwara - 1 in "l'"
... Cabinet response ff, Sōkai (minute) Dō・Tsokusode Seisho April 1983, ? IJ 1 Temple Head Office Director Kazuo Wakasugi 1, small corner display 11t I-! I"+'i?'l request No. 1945
No. i 2° Invention'> Name + 4・Coal. Liquefaction method 3, supplementary person i (relationship with 1 q, sd't-111+Ipr
1 person fi: +i+i 5-1-4 Marunouchi Otsu-chome, Chiyoda-ku, Tokyo;
No. 1 left / Bolt r (Vllll building ili story (504) 1
894 No. 1 (No. 1)
]791 out of 111 Akira (and 1 other person) 5, ? 11i/J spontaneous correction 6 of 11i+l instruction
, ? 1li1 [Increased Claims of the Invention Nonel Item ``Scope of Claims'' of the Specification Subject to the Amendment a. Contents of the Amendment The ``Scope of Claims'' of the Specification of the Amendment will be corrected as shown in the attached sheet. 2. Claims Asphaltene as a coal metal in the presence of a hydrogen-donating solvent! A first step of converting the product slurry f:N to a product slurry consisting primarily of asphaltenes.
i-Mo system and/or Co-M. In a two-stage coal liquefaction method consisting of a second step of hydrotreating in the presence of a catalyst containing sulfides of metals of 5 wt% or more of hydrogenated coal liquefied oil with a boiling point of 200°C or higher is extracted as a hydrogen-donating solvent,
The first step includes a step of treating coal using the same at a temperature of 200 to 320°C and under a pressure higher than the vapor pressure of the hydrogenated coal liquefied oil at 520°C for at least 5 minutes. A method for liquefying coal, characterized in that it is added as a pre-treatment step. 563-

Claims (1)

Claims: A first step of converting coal to a product slurry consisting primarily of asphaltenes in the presence of a hydrogen-donating solvent, followed by a product slurry consisting primarily of asphaltenes f, Ni-
Mo-based and/or ViCo-+J. In the step-stage coal liquefaction method, which consists of a second step of hydrotreating in the presence of a catalyst containing sulfides of metals of Hydrogenated coal liquefied oil containing 5vt% or more and having a boiling point of 200°C or higher is taken out as a hydrogen-donating solvent, and using this, coal is heated under a temperature condition of 200 to 520°C and 520% of the hydrogenated coal liquefied oil is A method for liquefying coal, characterized in that a step of treating it for at least 5 hours under a pressure condition equal to or higher than the vapor pressure at °C is divided into months as a pretreatment step of the first step of step iq.